[Lesleyk]

Despite netting - which I have done successfully in previous years - the little blighters have made their way in and on inspection this morning I find my Brussels looking very sad indeed - some leaves have been completely decimated overnight!  So, as I like to garden organically, as far as possible, is there anything I can do at this stage to stop it getting any worse?  I looked and couldn't find any caterpillars - plenty of poo, though - so couldn't do any hand-picking.  Is there anything else - something organic I can spray them with, for example?  Having watched the Brussels - and broccoli  - growing so beautifully, I'm really quite upset to see this ......

[mumofstig]

If you can't see any caterpillars, which is strange, was it actually slugs n snails that did the damage? They're better at hiding 

[Nobbie]

If I can't see any catapillers then I give the plant a good shake and check the ground carefully. Did a quick check on my broccoli yesterday and there were some single tiny catapillers on about half the leaves. Looks like it's time for a squishing session before they do any damage

[rosiecider]

I read I think in the Gardeners World to douse cabbages in very salty water and the caterpillars drop to the ground then you can squish them

[mobilekat]

I pull the little blighters off and then chuck them under the bird feeders- within seconds the robin and bluetits appear
I have requested we miss out the middle man (or woman) and they pick them off the plants, but apparently thats boring!

[Goosegirl]

The poo should give you a clue as to what has been at them. Caterpillar poo are like little dots and snail poo is longer plus the tell-tale trails. If you had nets over them, then perhaps the leaves were touching the net top so allowing the CWs to lay their eggs through it. What a shame, but hopefully they can still be saved. Salty water should run off the leaves and not trouble your plants, so see what you get.

[Lesleyk]

The poo should give you a clue as to what has been at them. Caterpillar poo are like little dots and snail poo is longer plus the tell-tale trails. If you had nets over them, then perhaps the leaves were touching the net top so allowing the CWs to lay their eggs through it. What a shame, but hopefully they can still be saved. Salty water should run off the leaves and not trouble your plants, so see what you get.

It's definitely cabbage white poo - and the holes and damage are a dead giveaway.  I think you might be right about the tops of the plants touching the netting - didn't think of that!  I'll give the salty water treatment a go and hope something can be salvaged.  Amazing how quickly they can make their way through the plants - there was no sign of anything a couple of days ago!